A Novel Gelatinase from Marine Flocculibacter collagenilyticus SM1988: Characterization and Potential Application in Collagen Oligopeptide-Rich Hydrolysate Preparation.

Although the S8 family in the MEROPS database contains many peptidases, only a few S8 peptidases have been applied in the preparation of bioactive oligopeptides. Bovine bone collagen is a good source for preparing collagen oligopeptides, but has been so far rarely applied in collagen peptide preparation. Here, we characterized a novel S8 gelatinase, Aa2_1884, from marine bacterium Flocculibacter collagenilyticus SM1988T, and evaluated its potential application in the preparation of collagen oligopeptides from bovine bone collagen. Aa2_1884 is a multimodular S8 peptidase with a distinct domain architecture from other reported peptidases. The recombinant Aa2_1884 over-expressed in Escherichia coli showed high activity toward gelatin and denatured collagens, but no activity toward natural collagens, indicating that Aa2_1884 is a gelatinase. To evaluate the potential of Aa2_1884 in the preparation of collagen oligopeptides from bovine bone collagen, three enzymatic hydrolysis parameters, hydrolysis temperature, hydrolysis time and enzyme-substrate ratio (E/S), were optimized by single factor experiments, and the optimal hydrolysis conditions were determined to be reaction at 60 ℃ for 3 h with an E/S of 400 U/g. Under these conditions, the hydrolysis efficiency of bovine bone collagen by Aa2_1884 reached 95.3%. The resultant hydrolysate contained 97.8% peptides, in which peptides with a molecular weight lower than 1000 Da and 500 Da accounted for 55.1% and 39.5%, respectively, indicating that the hydrolysate was rich in oligopeptides. These results indicate that Aa2_1884 likely has a promising potential application in the preparation of collagen oligopeptide-rich hydrolysate from bovine bone collagen, which may provide a feasible way for the high-value utilization of bovine bone collagen.

Potential of Thermolysin-like Protease A69 in Preparation of Bovine Collagen Peptides with Moisture-Retention Ability and Antioxidative Activity.

Bovine bone is rich in collagen and is a good material for collagen peptide preparation. Although thermolysin-like proteases (TLPs) have been applied in different fields, the potential of TLPs in preparing bioactive collagen peptides has rarely been evaluated. Here, we characterized a thermophilic TLP, A69, from a hydrothermal bacterium Anoxybacillus caldiproteolyticus 1A02591, and evaluated its potential in preparing bioactive collagen peptides. A69 showed the highest activity at 60 °C and pH 7.0. We optimized the conditions for bovine bone collagen hydrolysis and set up a process with high hydrolysis efficiency (99.4%) to prepare bovine bone collagen peptides, in which bovine bone collagen was hydrolyzed at 60 °C for 2 h with an enzyme-substrate ratio of 25 U/g. The hydrolysate contained 96.5% peptides that have a broad molecular weight distribution below 10000 Da. The hydrolysate showed good moisture-retention ability and a high hydroxyl radical (•OH) scavenging ratio of 73.2%, suggesting that the prepared collagen peptides have good antioxidative activity. Altogether, these results indicate that the thermophilic TLP A69 has promising potential in the preparation of bioactive collagen peptides, which may have potentials in cosmetics, food and pharmaceutical industries. This study lays a foundation for the high-valued utilization of bovine bone collagen.

Repair of alveolar cleft bone defects by bone collagen particles combined with human umbilical cord mesenchymal stem cells in rabbit.

BACKGROUND: Alveolar cleft is a type of cleft lip and palate that seriously affects the physical and mental health of patients. In this study, a model of the alveolar cleft phenotype was established in rabbits to evaluate the effect of bone collagen particles combined with human umbilical cord mesenchymal stem cells (HUC-MSCs) on the repair of alveolar cleft bone defects. METHODS: A model of alveolar clefts in rabbits was established by removing the incisors on the left side of the upper jaw bone collagen particles combined with HUC-MSCs that were then implanted in the defect area. Blood biochemical analysis was performed 3 months after surgery. Skull tissues were harvested for gross observation, and micro-focus computerised tomography (micro-CT) analysis. Tissues were harvested for histological and immunohistochemical staining. The experiments were repeated 6 months after surgery. RESULTS: Bone collagen particles and HUC-MSCs showed good biocompatibility. Bone collagen particles combined with HUC-MSCs were markedly better at inducing bone repair and regeneration than bone collagen particles alone. CONCLUSIONS: Combining HUC-MSCs with bone collagen particles provides a simple, rapid and suitable method to fill a bone defect site and treat of alveolar cleft bone defects.

Multiproxy isotopic analyses of human skeletal material from Rapa Nui: Evaluating the evidence from carbonates, bulk collagen, and amino acids.

OBJECTIVES: Stable isotope ratio analysis of bulk bone collagen dominates research into past diet; however, bone carbonate and compound specific isotope analyses (CSIA) of amino acids provide alternative, yet complementary, lines of evidence toward that same research goal. Together they inform on different aspects of diet, allowing greater certainty in reconstructions. Here we present new data on carbonate isotopes for Rapa Nui and reevaluate prehistoric diet in the context of these new and previously published bulk collagen and CSIA data. MATERIALS AND METHODS: We analyzed carbon isotopes in bone carbonate from 28 prehistoric human teeth from Rapa Nui. These represent a subset of material examined previously for carbon and nitrogen isotope ratios in bulk collagen. We then reevaluate prehistoric diet in light of these and other published data. In addition, we analyzed carbon and nitrogen isotope ratios in 28 modern plant specimens from Rapa Nui to better approximate the isotopic value of the terrestrial endmember. RESULTS: Bulk data suggest a predominantly terrestrial diet, with the amount of marine sources incorporated varying though time. While previously argued to reveal greater amounts of marine consumption, reanalysis of recently published CSIA data suggests this result may relate to the proportion of carbon assimilated rather than consumed. Utilizing models incorporating concentration dependence for estimating dietary proportions results in much lower estimates of marine consumption, in line with findings of the bulk data. DISCUSSION: While these data indicate a larger focus on terrestrial resources, limitations in all forms of analysis make it difficult to determine exact dietary contributions in this mixed system. Better understanding of the complex physiological processes governing isotopic routing and fractionation, and knowledge of appropriate isotopic endmember values are needed to advance this research.

[Marine fish bone collagen oligopeptide combined with calcium aspartate increases bone mineral density in obariectomized rats].

OBJECTIVE: To investigate the effect of marine fish collagen oligopeptide and calcium aspartate alone or in combination on bone mineral density in ovariectomized rats. METHODS: Sixty three-month-old SPF Wistar female rats were randomly divided into 6 groups according to their body weight: sham operation group, model control group(ovariectomy), calcium aspartate group(ovariectomy), marine fish collagen oligopeptide group(ovariectomy), aspartate calcium + marine fish collagen oligopeptide group(ovariectomy) and calcium carbonate control group(ovariectomy), 10 rats in each group. The sham operation group and the model control group were given the same volume of pure water by gavage, and the other groups were intragastrically administered with calcium aspartate(116. 7 mg/kg), marine fish collagen oligopeptide(250 mg/kg), calcium aspartate(116. 7 mg/kg) + marine fish collagen oligopeptide(250 mg/kg), calcium carbonate(35. 6 mg/kg), and the test substance was continuously administered for 90 days. After 90 days, the animals were sacrificed, and the liver and kidney of the rats were taken to calculate the organ coefficient and pathological examination. The rat femurs were taken to measure bone mineral density and bone calcium content and rat serum was used to determine serum calcium, phosphorus concentration and alkaline phosphatase(ALP) activity. RESULTS: Bone mineral density and bone calcium content in the model group were significantly lower than those in the sham operation group(P<0. 05), indicating that the osteoporosis model was successfully established by oophorectomy. There was no significant difference in the organ index of each group(P>0. 05), liver/kidney HE staining microscopic examination showed no abnormal changes, indicating the safety of the test substances. The bone mineral density of the aspartate calcium + marine fish collagen oligopeptide group was significantly greater than that of the model group(P<0. 05). The bone mineral density of the aspartate calcium group and the marine fish collagen oligopeptide group was larger than that of the model group, but there was no significant difference(P>0. 05). Compared with that in the model group, the calcium content of calcium aspartate + marine fish collagen oligopeptide group was significantly higher(P<0. 05). Compared with that in the calcium aspartate group, the calcium content of calcium aspartate + marine fish collagen oligopeptide group was higher(P<0. 05), there was no significant difference in serum calcium concentration between groups(P>0. 05). Compared with that in the model group, serum phosphorus concentration in the aspartate calcium group, marine fish collagen oligopeptide group, aspartate calcium + marine fish collagen oligopeptide group was significantly higher(P<0. 05) and ALP activity was significantly reduced(P<0. 05). CONCLUSION: The combination of calcium aspartate and marine fish collagen oligopeptide has a significant effect on increasing bone mineral density, also indicating that marine fish bone collagen oligopeptide could promote absorption of calcium aspartate.

Breastfeeding, weaning, and dietary practices during the Western Zhou Dynasty (1122-771 BC) at Boyangcheng, Anhui Province, China.

OBJECTIVES: Here we investigate breastfeeding and weaning practices and adult dietary habits at the Western Zhou Dynasty (1122-771 BC) site of Boyangcheng () located in Anhui Province, China. In addition, we utilize the differences in bone collagen turnover rates between rib and long bones from the same individual to examine past life histories, such as changes in diet or residence. MATERIALS AND METHODS: Bone collagen from both the rib and long bones (either femora or humeri) of 42 individuals was measured for stable isotope ratios of carbon (δ13 C) and nitrogen (δ15 N). In addition, δ13 C and δ15 N values are reported for 35 animals (dogs, cows, horses, pigs, and deer). RESULTS: The human δ13 C values range from -20.7‰ to -12.0‰ with a mean value of -18.8 ± 1.6‰. The human δ15 N values range from 9.1‰ to 13.4‰ with a mean value of 10.9 ± 1.0‰. The animals display a wide range of δ13 C (-21.5‰ to -8.2‰; -15.8 ± 4.5‰) and δ15 N values (4.0‰ to 9.5‰; 6.5 ± 1.8‰). CONCLUSIONS: The adult δ13 C and δ15 N results indicate that mixed C3 (rice) and C4 (millet) terrestrial diets with varying levels of animal protein (mostly pigs and deer) were consumed. The elevated subadult δ15 N results return to adult levels by approximately 3-4 years of age, indicating that the weaning process was completed during this period. Individuals between 2 and 10 years old, with lower δ13 C and δ15 N results than the adult mean, possibly consumed more plant-based diets, and this is consistent with Chinese medical teachings ∼1500 years later during the Tang Dynasty (AD 618-907). The isotopic offsets between the ribs and long bones revealed that five adults experienced dramatic dietary shifts in their later lives, switching from predominately C3 /C4 to C3 diets. This research provides the first isotopic information about ancient Chinese breastfeeding and weaning practices and establishes a foundation for future studies to examine diachronic trends.

Ecological and cultural shifts of hunter-gatherers of the Jomon period paralleled with environmental changes.

OBJECTIVES: Holocene hunter-gatherers adapted to climatic and environmental changes over time. Carbon and nitrogen stable isotope analysis of human skeletal remains from the Inariyama shell mound of the Final Jomon period have revealed large dietary variations in the population. This study analyzed radiocarbon dates of these individuals to test temporal changes in diet and its relationship with tooth ablation. MATERIALS AND METHODS: Twenty-nine human skeletal remains from Inariyama were included in this study. Extracted bone collagen samples were purified to graphite. Then, radiocarbon dating of these samples was performed using the accelerator mass spectrometer. RESULTS: The radiocarbon ages of Inariyama ranged about, 3,230-2,140 cal BP and showed three peaks of occupation. In the early and late phases, terrestrial resource consumption and incisor extraction were observed, while marine resource consumption and canine extraction were observed in the middle phase. DISCUSSION: These temporal changes of diet and tooth ablation types occurred in parallel with climatic cooling and environmental change and help reveal how Holocene hunter-gatherers adapted to the changing environments.

Beneficial impact of zinc supplementation on the collagen in the bone tissue of cadmium-exposed rats.

Cadmium (Cd) is a toxic metal that damages bone tissue by affecting its mineral and organic components. The organic matrix is mainly (90%) composed of collagen, which determines the biomechanical strength of bone. The aim of this study was to evaluate the effect of zinc (Zn) supplementation (30 or 60 mg l-1 ) under moderate and relatively high exposure to Cd (5 and 50 mg l-1 ) on collagen in the rat tibia proximal epiphysis and diaphysis (regions abundant in trabecular and cortical bone, respectively). Significant decrease in collagen type I biosynthesis was found in both regions of the tibia in Cd-treated rats, whereas the supplementation with Zn provided significant protection against this effect. Western blot confirmed the presence of the major type I collagen in the tibia epiphysis and diaphysis, but collagen type II was revealed only in the epiphysis. Acetic acid- and pepsin-soluble collagen concentration in the tibia epiphysis and diaphysis was significantly increased due to the exposure to Cd, whereas the supplementation with Zn protected, partially or totally, from these effects, depending on the used concentration. The supplementation with Zn also provided protection from unfavorable Cd impact on the maturation of the bone collagen, as the ratio of cross-links to monomers was higher compared to the Cd-treated group. This report confirms our previous findings on the preventive action of Zn against harmful effects of Cd on bone, but additionally, and to the best of our knowledge for the first time, explains the possible mechanism of the beneficial influence of this bioelement.

Investigating economic specialization on the central Peruvian coast: A reconstruction of Late Intermediate Period Ychsma diet using stable isotopes.

OBJECTIVES: Hypothetical models of socioeconomic organization in pre-Columbian societies generated from the rich ethnohistoric record in the New World require testing against the archaeological and bioarchaeological record. Here, we test ethnohistorian Maria Rostworowski's horizontality model of socioeconomic specialization for the Central Andean coast by reconstructing dietary practices in the Late Intermediate Period (c. AD 900-1470) Ychsma polity to evaluate complexities in social behaviors prior to Inka imperial influence. MATERIALS AND METHODS: Stable carbon and nitrogen isotope analysis of archaeological human bone collagen and apatite (δ13 Ccol[VPDB], δ15 Ncol[AIR] , δ13 Cap[VPDB] ) and locally available foods is used to reconstruct the diets of individuals from Armatambo (n = 67), associated ethnohistorically with fishing, and Rinconada Alta (n = 46), associated ethnohistorically with agriculture. RESULTS: Overall, mean δ15 Ncol[AIR] is significantly greater at Armatambo, while mean δ13 Ccol[VPDB] and mean δ13 Cap[VPDB] are not significantly different between the two sites. Within large-scale trends, adult mean δ13 Cap[VPDB] is significantly greater at Armatambo. In addition, nearly one-third of Armatambo adults and adolescents show divergent δ15 Ncol[AIR] values. DISCUSSION: These results indicate greater reliance on marine resources at Armatambo versus Rinconada Alta, supporting the ethnohistoric model of socioeconomic specialization for the Central Andean coast. Deviations from large-scale dietary trends suggest complexities not accounted for by the ethnohistoric model, including intra-community subsistence specialization and/or variation in resource access.

Species Identification of Bovine, Ovine and Porcine Type 1 Collagen; Comparing Peptide Mass Fingerprinting and LC-Based Proteomics Methods.

Collagen is one of the most ubiquitous proteins in the animal kingdom and the dominant protein in extracellular tissues such as bone, skin and other connective tissues in which it acts primarily as a supporting scaffold. It has been widely investigated scientifically, not only as a biomedical material for regenerative medicine, but also for its role as a food source for both humans and livestock. Due to the long-term stability of collagen, as well as its abundance in bone, it has been proposed as a source of biomarkers for species identification not only for heat- and pressure-rendered animal feed but also in ancient archaeological and palaeontological specimens, typically carried out by peptide mass fingerprinting (PMF) as well as in-depth liquid chromatography (LC)-based tandem mass spectrometric methods. Through the analysis of the three most common domesticates species, cow, sheep, and pig, this research investigates the advantages of each approach over the other, investigating sites of sequence variation with known functional properties of the collagen molecule. Results indicate that the previously identified species biomarkers through PMF analysis are not among the most variable type 1 collagen peptides present in these tissues, the latter of which can be detected by LC-based methods. However, it is clear that the highly repetitive sequence motif of collagen throughout the molecule, combined with the variability of the sites and relative abundance levels of hydroxylation, can result in high scoring false positive peptide matches using these LC-based methods. Additionally, the greater alpha 2(I) chain sequence variation, in comparison to the alpha 1(I) chain, did not appear to be specific to any particular functional properties, implying that intra-chain functional constraints on sequence variation are not as great as inter-chain constraints. However, although some of the most variable peptides were only observed in LC-based methods, until the range of publicly available collagen sequences improves, the simplicity of the PMF approach and suitable range of peptide sequence variation observed makes it the ideal method for initial taxonomic identification prior to further analysis by LC-based methods only when required.

Preparation of highly and generally enriched mammalian tissues for solid state NMR.

An appreciable level of isotope labelling is essential for future NMR structure elucidation of mammalian biomaterials, which are either poorly expressed, or unexpressable, using micro-organisms. We present a detailed protocol for high level (13)C enrichment even in slow turnover murine biomaterials (fur keratin), using a customized diet supplemented with commercial labelled algal hydrolysate and formulated as a gel to minimize wastage, which female mice consumed during pregnancy and lactation. This procedure produced approximately eightfold higher fur keratin labelling in pups, exposed in utero and throughout life to label, than in adults exposed for the same period, showing both the effectiveness, and necessity, of this approach.

Isotopic evidence for divergent diets and mobility patterns in the Atacama Desert, northern Chile, during the Late Intermediate Period (AD 900-1450).

The decline of the Tiwanaku state saw the emergence of two new cultures-Pica-Tarapacá and Atacama-during the Late Intermediate Period in northern Chile. Archeological evidence suggests that both groups practised maize agriculture and pastoralism, but that their interaction zones differed significantly. Marine resources are common at Pica-Tarapacá sites, even those far from coast, while Atacama sites in the desert oases and precordilleran area seem to have directed their networks towards the highlands. Here we apply stable carbon, nitrogen, and oxygen isotope analysis on human bone and enamel to test dietary patterns and residential mobility at two sites, Pica 8 and Quitor 6, representing the Pica-Tarapacá and Atacama cultures, respectively. Our results show that diet at the two sites indeed differed: significant but variable consumption of marine resources and maize is indicated at Pica 8, despite being an inland site, while diet at Quitor 6 was based mainly on terrestrial resources. The use of seabird guano and llama dung as fertilizers and extreme aridity may have contributed to the high nitrogen isotope values observed in Pica 8 humans. The δ(18) O values in Pica 8 individuals are generally lower than for Quitor in spite of its greater distance from the Andes. All three isotopes suggest the presence of at least five nonlocals in the 30 measured at Pica 8. This evidence for human mobility is consistent with the high levels of trade and interaction observed in the archeological record, and begins to quantify the degree of movement of specific individuals.

Isolation, purification, and antiosteoporosis activity of donkey bone collagen from discarded bone and its antioxidant peptides.

Oxidative stress plays a crucial role in the development of osteoporosis. In this study, it was observed that donkey bone collagen (DC) at a concentration of 500 µg/mL scavenged 17.89 % of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radicals, indicating its antioxidant properties. Additionally, when an oxidative damage osteoblast model was created using H2O2, 100 µg/mL DC demonstrated the ability to enhance cell survival by 27.31 %. Furthermore, 50 µg/mL DC increased the intracellular differentiation marker alkaline phosphatase (ALP) level by 62.65 %. Additionally, the study revealed that DC significantly increased the expression of osteoporosis-related factors in serum and effectively restored the abnormal structure of spongy bone in mice osteoporosis model. Peptides (GGWFL, ANLGPA, and GWFK) isolated from DC through gastrointestinal digestion and subsequent enzymatic purification in vitro demonstrated the ability to safeguard osteoblasts from H2O2-induced damage by reducing intracellular reactive oxygen species (ROS). This protection resulted in enhanced cell survival and promoted osteoblast differentiation. This investigation underscores that DC can shield oxidative damage osteoblast model from oxidative stress, ameliorate osteoporosis, and enhance bone density in mice osteoporosis model. These findings suggest various DC applications in the food and medicine industries.

Forensic application of isotope ratio mass spectrometry (IRMS) for human identification.

Application of isotope ratio mass spectrometry (IRMS) to skeletal remains has become an important tool to investigate human behavior and history. Isotopic variations in collagen, enamel, and keratin reflect variations in an individual's diet and drinking water. Since food and water sources typically are geographically linked, isotope testing can assist in forensic identification by classifying remains to a likely geographic or population origin. If remains are commingled, differences in diet or geographic origin also can support their separation. The usefulness of IRMS in forensic science is dependent on the underlying quality and surety of the isotope test results; in other words, we need to understand their reliability in interpretations. To take ownership of isotopic data quality, we recommend asking a series of questions:Here, we use data collected during the buildout and accreditation of an isotope testing program at the Defense POW/MIA Accounting Agency (DPAA) to answer the above questions for the forensic application of IRMS for human identification. While our primary focus is on the preparation and analysis of bone collagen, the questions above should be considered whenever isotope testing is used in forensic casework. Whether the populations of interest are drugs or humans, olives or explosives, users need to evaluate their isotopic data and interpretations to ensure they are scientifically sound and legally defensible.

A physicochemical evaluation of ossein-hydroxyapatite within the bovine bone matrix revealed demineralization and making type I collagen available as a result of processing and solubilization by acids.

Bovine bone is an animal-origin matrix rich in type I collagen (COL I) and it necessitates prior demineralization and makes COL I available. This study investigated the ossein-hydroxyapatite physicochemical properties evaluation as a result of processing and solubilization by acids and revealed the bone matrix demineralization and making COL I available. The tibia residue from bovine sources was processed, ground, and transformed into bone matrix powder. The bone matrix was solubilized in acetic acid followed by lactic acid. The bone matrix was evaluated as a result of processing and solubilization by acids: ossein and hydroxyapatite percentages by nitrogen and ash content, mineral content, particle size distribution, Fourier-transformation infrared spectroscopy, x-ray diffraction, and scanning electron microscope. For the obtained residual extracts, pH and mineral content were evaluated. The solubilization by acids affected the ossein-hydroxyapatite physicochemical properties, and the bone matrix solubilized by acetic and lactic acid showed the preservation of the ossein alongside the loss of hydroxyapatite. The processing and the solubilization by acids were revealed to be a  alternative to bone matrix demineralization and enabling the accessibility of bone COL I. PRACTICAL APPLICATION: Bovine bone is an abundant type I collagen source, but processing maneuvers and demineralization effect present limitations due to the rigidity of the structural components. Exploring methodologies to process and demineralize will allow type I collagen to be obtained from the bone source, and direct and amplify the potentialities in the chemical and food industries. The research focused on bone sources and collagen availability holds paramount significance, and promotes repurposing agribusiness residues and development of protein-base products.

Phosphorylation modification of bovine bone collagen peptide enhanced its effect on mineralization of MC3T3-E1 cells via improving calcium-binding capacity.

This study aimed to investigate the effect of phosphorylation modification of collagen peptide on its calcium-binding capacity and pro-mineralization activity. In this study, collagen peptide (Leu-Thr-Phe, LTF) and phosphorylated LTF (P-LTF) were synthesized and further chelated with calcium ions. The results showed that phosphorylation of LTF significantly enhanced its calcium-binding capacity. Spectra analysis revealed that the calcium-binding sites of P-LTF were mainly carbonyl, carboxyl, and phosphate groups. Molecular docking further demonstrated that the phosphate group introduced by phosphorylation enhanced the calcium-binding capacity of LTF by ionic bonds and coordination bonds. The stability analysis results suggested that intestinal fluid could repair the peptide-calcium complex destroyed by gastric fluid. The cell experiment displayed that P-LTF-Ca significantly improved the mineralization activity of MC3T3-E1 cells, and the order of effective influence was P-LTF-Ca > LTF-Ca > P-LTF > LTF. This study provided the theoretical basis for the potential application of phosphorylation modification in improving bone health.

Bomb pulse 14 C evidence for consistent remodeling rates of cortical femur collagen in middle-late adulthood.

OBJECTIVES: Bomb pulse (BP) radiocarbon (14 C) dating methods are used by forensic anthropologists to estimate the year-of-death (YOD) of unidentified individuals. Method resolution and accuracy depend on establishing lag times, or the difference between a tissue's BP 14 C-derived year and the YOD, of various tissue types from known deceased persons. Bone lag times span many years and are thought to increase with age as a function of slowing remodeling rates. However, remodeling rates for various skeletal elements, bone structures and phases are not well known. MATERIALS AND METHODS: Here a simple method is used to estimate bone remodeling rates from a compilation of published cortical femur bone collagen BP 14 C measurements (n = 102). Linear regression models and nonparametric tests are used to detect changes in lag times and remodeling rates with increasing age-at-death. RESULTS: Remodeling rates and lag times of 3.5%/year and 29 years, respectively, are estimated from individuals aged 40-97 years. In contrast to previous work, the analysis yielded modest and negligible changes in remodeling rates and lag times with advancing age. Moreover, statistically significant differences in remodeling rates and lag times were not found between reported females and males. DISCUSSION: Implications for the temporal contexts within an individual's lifetime of biogeochemical data in archaeology and forensic anthropology are discussed, warranting additional BP 14 C studies of known individuals and integration with histomorphometric analysis.

Reconstructing dietary practices at Tell Kamid el-Loz (Lebanon) during the Bronze and Iron Age III / Persian to Hellenistic periods using plant micro-remains from dental calculus and stable isotope analysis of bone collagen.

Tell Kamid el-Loz (Lebanon) was an important Bronze Age urban center that dominated one of the central crossroads of the Ancient Near East, connecting Egypt and the Levant with northern Mesopotamia, Anatolia, and Syria, as well as the interior with the Mediterranean coast. However, by the early Iron Age, the site had shrunk to a small rural settlement. Later, in the Iron Age III / Persian-Hellenistic, only enigmatic pits and a large cemetery remained. In this paper, we analyzed plant micro-remains from the dental calculus of 15 individuals (3 from the Middle Bronze Age II and 12 from the Iron Age III / Persian-Hellenistic) and δ 13C and δ 15N stable isotope data from tbulk bone collagen of 74 individuals (10 from the Middle Bronze Age II and 64 from the Iron Age III / Persian-Hellenistic) and 13 Late Bronze Age animal bones (7 Ovis/Capra and 6 Bos). Our results indicate general stability of human diet throughout the Middle Bronze Age II and the Iron III / Persian-Hellenistic periods, with a reliance on C3 plant crops and terrestrial animals also consuming C3 plants. In the later period, the plant micro-remains indicate the consumption of C4 plants and sedges, and the stable isotope analysis indicates differences in diet between males and females. Supplementary Information: The online version contains supplementary material available at 10.1007/s12520-024-02000-w.

Novel osteogenic peptide from bovine bone collagen hydrolysate: Targeted screening, molecular mechanism, and stability analysis.

This study aimed to screen for a novel osteogenic peptide based on the calcium-sensing receptor (CaSR) and explore its molecular mechanism and gastrointestinal stability. In this study, a novel osteogenic peptide (Phe-Ser-Gly-Leu, FSGL) derived from bovine bone collagen hydrolysate was successfully screened by molecular docking and synthesised by solid phase peptide synthesis for further analysis. Cell experiments showed that FSGL significantly enhanced the osteogenic activity of MC3T3-E1 cells by acting on CaSR, including proliferation (152.53%), differentiation, and mineralization. Molecular docking and molecular dynamics further demonstrated that FSGL was a potential allosteric activator of CaSR, that turned on the activation switch of CaSR by closing the Venus flytrap (VFT) domain and driving the two protein chains in the VFT domain to easily form dimers. In addition, 96.03% of the novel osteogenic peptide FSGL was stable during gastrointestinal digestion. Therefore, FSGL showed substantial potential for enhancing the osteogenic activity of osteoblasts. This study provided new insights for the application of CaSR in the targeted screening of osteogenic peptides to improve bone health.

The pore size of PLGA bone implants determines the de novo formation of bone tissue in tibial head defects in rats.

PURPOSE: The influence of the pore size of biodegradable poly(lactic-co-glycolic acid) scaffolds on bone regeneration was investigated. METHODS: Cylindrical poly(lactic-co-glycolic acid) scaffolds were implanted into a defect in the tibial head of rats. Pore sizes of 100-300, 300-500, and 500-710 µm were tested and compared to untreated defects as control. Two and four weeks after implantation, the specimens were explanted and defect regeneration and de novo extracellular matrix generation were investigated by MRI, quantitative solid-state NMR, and mass spectrometry. RESULTS: The pore size of the scaffolds had a pronounced influence on the quantity of the extracellular matrix synthesized in the graft; most collagen was synthesized within the first 2 weeks of implantation, while the amount of hydroxyapatite increased in the second 2 weeks. After 4 weeks, the scaffolds contained large quantities of newly formed lamellar bone while the control defects were filled by inhomogenous woven bone. Best results were obtained for scaffolds of a pore size of 300-500 µm. CONCLUSION: Our analysis showed that the structure and dynamics of the regenerated extracellular matrix was very similar to that of the native bone, suggesting that biomineralization was significantly enhanced by the choice of the most appropriate implant material.